Puran Free Disk Defrag is an excellent defragmentation tool with well thought-out features like boot time defrag (itself with several options), optimization (consolidates files to the faster areas of the disk for speedy access), and easy-to-grasp interface and automatic shutdown after the operation is done. On my machine, Puran defragged files left by several other defragmenters. Its optimization actually seemed to improve my computer's performance as well. Overall it is an impressive piece of software, and free to boot (no pun intended!). Nice job, Puran.
Price: Free review details